The catalyst of the present invention comprises palladium on a porous Silica glass.
Preferably the catalyst of the present invention is palladium on a porous Silica glass.
The porous Silica glass shows preferably the following characteristics:                a) a particle diameter in the range of 20 to 500 μm, preferably in the range of 50 to 400 μm, more preferably in the range of 80 to 300 μm, most preferably in the range of 100 to 200 μm; and/or        b) a pore size in the range of 10 to 400 nm; preferably in the range of 30 250 nm, more preferably in the range of 40 150 nm, most preferably in the range of 50 to 60 nm; and/or        c) a pore volume in the range of 100 to 5000 mm3/g; preferably in the range of 250 to 2500 mm3/g, more preferably in the range of 500 to 2000 mm3/g, most preferably in the range of 1000 to 1500 mm3/g; and/or        d) a specific surface in the range of 5 to 500 m2/g; preferably in the range of 25 to 300 m2/g, more preferably in the range of 40 to 250 m2/g, most preferably in the range of 50 to 200 m2/g.        
Preferably the porous Silica glass shows all characteristics a) to d), whereby the present invention encompasses any possible combination of the preferred/more preferred/most preferred characteristics.
Such porous Silica glasses are commercially available. An especially preferred one is sold under the trademark TRISOPERL® by the Schuller GmbH, Wertheim, Germany. TRISOPERL® is a porous Silica glass with an average particle size in the range of 100 to 200 μm, an average pore size of 54.47 nm, a specific surface of 93.72 m2/g and an average pore volume of 1255.5 mm3/g.